It now lives in vulkan_renderpass.c and takes most of its parameters
from plist configs (just the name (which is used to find the config),
output spec, and draw function from C). Even the debug colors and names
are taken from the config.
While looking at the deferred attachment images with using a template in
mind, I noticed that the opaque attachment was using 8-bit color. The
problem is, it's meant to be HDRI with the compose pass crunching it
down to LDRI. Switching to 16-bit float does seem to have made a subtle
difference (hey, it's still quake data, not much HDRI in there).
That certainly makes it nicer to work with large sets, and shows one way
to be careful with allocated resources: don't allocate them in the
inherited data and use a template that needs a few things filled in to
be valid. Also, it seems that overriding values in sub-structures "just
works" :)
This allows a single render pass description to be used for both
on-screen and off-screen targets. While Vulkan does allow a VkRenderPass
to be used with any compatible frame buffer, and vkparse caches a
VkRenderPass created from the same description, this allows the same
description to be used for a compatible off-screen target without any
dependence on the swapchain. However, there is a problem in the caching
when it comes to targeting outputs with different formats.
This means color, emission, and translucent. Fixes the HOM issues on my
VersaPro (but halves the frame-rate... definitely need to bring back the
forward renderer as an option).
I was reading about multi-pass rendering on mobile devices
(https://developer.oculus.com/blog/loads-stores-passes-and-advanced-gpu-pipelines/)
and discovered that I had used the wrong flags (but then, I think Graham
Sellers had, too, since used his Vulkan Programming Guide as a
reference). Doesn't seem to make any difference on desktop, but as
there's no loss there, but potential gains on mobile, I'd say it's a
win.
There were actually several problems: translucency wasn't using or
depending on the depth buffer, and the depth buffer wasn't marked as
read-only in the g-buffer pass. Getting that correct seems to have given
bigass1 a 0.5% boost (hard to say, could be the usual noise).
That was... easier than expected. A little more tedious that I would
have liked, but my scripting system isn't perfect (I suspect it's best
suited as the output of a code generator), and the C side could do with
a little more automation.
While I could reconstruct the position from the screen coords and depth,
this is easier and good enough for now. Reconstruction is an
optimization thing.
Lighting doesn't actually do lights yet, but it's producing pixels.
Translucent seems to be working (2d draw uses it), and compose seems to
be working.
After getting lights even vaguely working for alias models, I realized
that it just wasn't going to be feasible to do nice lighting with
forward rendering. This gets the bulk of the work done for deferred
rendering, but still need to sort out the shaders before any real
testing can be done.
